Yarn-tensioning device



Dec. 30, 1941. B CARTER ETAL 2,268,277

YARN-TENSIONING DEVICE Filed April 23, 1941 fNl/ENTOReS.

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A TTORNEY.

Patented Dec. 30, 1941 YARN-TENSIONING DEVICE Ben Carter and Eric Carter, Bolton, England Application April 23, 1941, Serial No. 389,872 In Great Britain March 29, 1940 6 Claims.

This invention relates to and consists of a yam-tensioning device, and is applicable inter alia to the tensioning of yarns being fed to the tension is readily adjustable within a wide range, and which is capable of use with yarns of the cheaper qualities which have occasional solid particles attached to them. With the types of tensioning device hitherto employed, where friction is applied to the yarn by passing the yarn between the members pressed together, or in a like manner, any solid particles carried by the yarn tend to obstruct the passage of the yarn through the tensioning devices and, by accumulating at the spring-pressed friction members, tend to hold those members apart and thus reduce or even eliminate the desired tensioning effect. This defect has meant that, where automatic stop mechanisms are provided, the undue ,slackening of the yarns due to the loss of tension has resulted in frequent stoppages of the machines. The present invention avoids these drawbacks and in addition makes possible the use of cheaper yarns, of inferior (uncleaned) quality, where, hitherto, the limitations posed by the tensioning devices have necessitated the use of better yarns.

Another object of the invention is to provide with such improved tensioning devices, improved automatic stop devices to operate in the event of a breakage in the yarn. which stop devices also are immune from interference by seeds or other clogs carried by the yarn. Finally, the invention contemplates a simplified general construction and arrangement of parts making the device adaptable for easy manufacture and assembly. I

According to the invention, the improved tensioning device comprises a fixed open-channelled yarn guide giving free passage to the yarn, and

a pair of additional yarn guides having external yarn-engaging parts, at least one of which lastnamed guides may be set in fixed positions in an orbital path, where it deflects the yarn, such additional yarn guides being on the supply side of the fixed yarn guide, and at least one of them (Cl. 242-153) having its yam-engaging surface adapted to impose a drag on the yarn.

In the preferred embodiments of the invention, the two additional yarn guides are adapted for simultaneous orbital movement about a fixed centre, and they each consist of a non-rotary, felt-covered or like friction roller or drum. Instead of felt, other material (e. g. some forms of rubber) having a drag effect on the yarn, may be employed to cover the non-rotary guides. The fixed guide may be of glass or porcelain, or metal, and will usually be of a quick-thread type, i. e. adapted to receive the yarns transversely.

In use, the yarns coming from a supply source, such as a series of cops, are passed first between the additional guides and then through the fixed guides, and the necessary tension is obtained by moving the orbital guide or guides to a point where the deflection of the yarn on its way from the supply to the fixed guide. and the consequent engagement of the yarn with the friction sur face offers the required resistance to the yarns movement. The relatively rough surface of the additional guide or guides not only provides the required tension, but allows seed and other matter sometimes found in yarn to pass over it without disadvantage. Also the rough surface has the effect of detaching some of those solid particles from the yarn.

According to another feature of the invention the improved tensioning device includes an insulated contact bar, and a number of slidable contact pins, the pins being mounted in a guide plate secured to the frame, and being looped to ride on the respective yarns as they pass to the fixed yarn guide. The pins are of a length such, and are positioned so that. when riding on unbroken yarns they are clear of the contact bar, but when a yarn breaks the associated pin falls on to that bar to complete an electric circuit to electric stop mechanism and thus stop the machine.

In the accompanying drawing Fig. 1 is an end view of a yarn-tensioning de- 4 vice according to the preferred form of the invention;

Fig. 2 is a plan of the same (the two views not being arranged in true projection); and

Fig. 3 is a diagram to illustrate another form of the invention.

some of the elements mentioned below. each end part I having two hollow bosses 2 and I, and also a right-angled recess or socket l. Mounted in the hollow boss 2 of each end part I is a round glass rod 5 forming a final yarn support, whilst mounted in insulating bushes la in the other hollow boss 3 of each end part I is a contact rod 8, supplied with suitable terminal connections I at one end. Secured in the said right-angled recess or socket l in the end parts I is an angle bar 8 forming a support for a porcelain thread guide 9, in one or more lengths,

which guide 9 has a number of open-topped undercut notches 9a of an open form, that is, of a form much larger than the yarn to be passed through them, into any one of which notches a yarn a: may be passed from the top, as it travels towards the glass rod 5. The end parts I are connected together by the elements 5, i and 8.

At each end of the angle bar 8 is mounted an arm in whose outer extremity is drilled to receive a short stud II projecting from the centre of a plate or bar l2, and between the two plates or bars I2. are mounted'a pair of non-rotary felt-covered rollers IS. The said short studs II are screwed at their extremity, to receive a milled or knurled nut Ila by which the angle of the plates or bars I! with respect to the short arm Ill may be fixed. Rotation of the plates I2 about their studs II causes the non-rotary rollers ii to move in an orbital path around the axis of the studs II.

The supporting frame also includes a projecting lug, or bracket is by which the whole device may be fixed in position on a machine.

Secured to the said end parts I, above the contact rod 6, is a trough-sectioned bar l5, whose edges are notched to form, in conjunction with a cross piece It extending from end part I to end part I, guides for a number of wire strips ii. The upper end of each strip I1 is looped to receive a yarn, and when resting on a taut yarn as shown in Fig. 1, its lower end is heldclear of and a slight distance away from the contact bar 6. If a yarn breaks or becomes unduly slack, the associated wire strip ll drops, on to the bar 5 and by so doing establishes electrical connection between the bar 5 and the bar l5, earths the bar 5, and operates stop-mechanism (not shown) to stop the machine.

In use, the yarn ends are first passed between the two rollers I3, then into the notched porcelain bar 9, then through the wire loops l1 and finally over the glass rod 5 to the working parts of the machine (not shown). By slackening the nuts Na and revolving the rollers l3 bodily around them, the yarns a: may be deflected until they have so much contact with the friction surfaces as will give the desired tension whereon the nuts Ila are re-tightened. The tension of the yarns may also be varied slightly by varying the notches in the porcelain bar.

As applied to a machine according to our said earlier application No. 305,986, there will be four of the improved tensioning devices, one at each side of each knitting head, and each tensioning device will control four yarns coming from a creel of four cops.

Referring now to Fig. 3, only one of the fric-- tion rollers I3 has an orbital movement, such movement being around the axis of the other roller I3. This arrangement requires a greater angular displacement of the roller to obtain the same deflection of yarn as in the first example described, but thereby allows of finer adjustment, and moreover the angular relationship of the yarn to the base of the notches la in the guides 8 is fixed.

In either of the examples illustrated, one only of the rollers I! may be non-rotary in cases where a less amount of drag is required. Accordingly, the spindles of the rollers ll may have means for arresting them or freeing them, at will.

What we claim is:

l. A yarn-tensioning device, comprising a frame for attachment to the machinery, a pair of non-rotary yam-deflecting rollers revolubly mounted for simultaneous movement in the frame, clamping means to hold the rollers in any set position in their path of revolution, each roller being covered with friction material to impose a drag on the yarn, and a fixed yarn guide carried by the frame, having a series of open-topped undercut notches to receive the yarn transversely.

2. A yarn-tensioning device, comprising a frame for attachment to the machinery, a pair of non-rotary yam-deflecting rollers in the frame, one fixed and the other revolvable about the first, clamping means to hold the revolvable roller in any set position in its path of revolution, each roller being covered with friction material to impose a drag on the yarn, and a fixed yarn guide carried by the frame, having a series of open-topped undercut notches to receive the yarn transversely.

3. A yarn-tensioning device, comprising a frame for attachment to the machinery, a pair of non-rotary yam-deflecting rollers revolubly mounted for simultaneous movement in the frame, clamping means to hold the rollers in any set position in their path of revolution, each roller being covered with friction material to impose a drag on the yarn, and a fixed yarn guide carried by the frame, having a series oi open-topped undercut notches to receive the yarn transversely, an insulated contact bar in the frame, a final yarn support in the frame, a series of contact members shaped to float on taut yarns passing from the fixed yarn guide to the final yarn support, guide means to direct the contact members on to the insulated contact bar when not floating on a taut yarn, and means to connect the contact bar and the said guide means to the circuit of electric stop mechanism.

4. A yarn-tensioning device, comprising a frame for attachment to the machinery, a pair of non-rotary yarn-deflecting rollers in the frame, one fixed and the other revolvable about the first, clamping means to hold the revolvable roller in any set position in its path of revolution, each roller being covered with friction material to impose a drag on the yarn, and a fixed yarn guide carried by the frame, having a series of open-topped undercut notches to receive the yarn transversely, an insulated contact bar in the frame, a final yarn support in the frame, a series of contact members shaped to float on taut yarns passing from the fixed yarn guide to the final yarn support, guide means to direct the contact members on to the insulated contact bar when not floating on a taut yarn, and means to connect the contact bar and the said guide means to the circuit of electric stop mechanism.

5. A yarn-tensioning device, comprising two frame ends, a glass rod, an insulated contact bar and an angle'member carried by and con- "ber and having open-topped undercut yarn-guiding notches therein, a pair 01' arms extending from the frame, a plate pivotally connected to the outer end of each arm, a pair of felt-covered yam-deflecting rollers non-rotatably carried by those plates and screw means to clamp the plates the outer end 01' each arm, a pair of felt-covered yarn-deflecting rollers non-rotatably carried by those plates, screw means to clamp the plates in any set position about their pivots and a series of contact members in guides above the contact bar, those members being 01 a length such as to be clear of the bar when floating on taut yarns passing from the fixed yarn guide to the glass rod, with means for connecting the contact bar and contact members in the circuit of electric stop mechanism.'

BEN CAR'I'ER. ERIC CARTER. 

